多强点信息补偿机载聚束式SAR中的运动误差

本文根据聚束式SAR相位误差的特性,采用基于Multi-PPP算法的多强点信息进行运动补偿.经过多强点信息补偿,不仅能消除由平动产生的空不变相差,而且能补偿由转动产生的空变相差.并分析了当聚束式SAR采用PFA成像时,为了精确补偿转动误差,多强点处理中第二强点和第三强点不应该分离,也研究了该方法中强点的选择和补偿效果等问题.最后给出了典型聚束式SAR采用PFA成像时经多强点信息补偿后的仿真结果.

Motion Compensation with Multi-PPP in Airborne Spotlight SAR

This paper applied prominent points' information based on multi PPP to compensate specific phase errors in spotlight SAR imaging.Among these points,the first one removes the phase errors from relative translation and produces a new focusing center,the second one is used to transform the rotational motion from unevenly to evenly,and the third one estimates the corresponding azimuth scaling factor.After this compensation,not only the space invariant phase errors but also the space variant phase errors are removed and high resolution SAR images can be produced.It's also analyzed that in PPP the second point can't be processed independently of the third point in order to correct precisely motion errors from spotlight SAR images with PFA.How to select the prominent points so as to improve PPP is also suggested in the paper.At last the method is proved to be feasible by the simulation results when PPP autofocus is embedded in spotlight SAR imaging with PFA.